Amethyst CADwizz Ultra
More than just a viewer !
View and print AutoCAD DWG and DXF versions 2.5 to 2010. Convert files to any version of AutoCAD. Convert files to a variety of image formats. Convert files to PDF and DWF.
Zoom, pan, and rotate AutoCAD DWG and DXF files:

Easily navigate drawings with the Thumbnail Explorer:
View and orbit 3D models with parallel or perspective projections: